On Mon, Oct 3, 2016 at 5:48 AM, Mykola Dvornik <mykola.dvor...@gmail.com> wrote:
> Hi Johan,
>
> Many thanks for your reply. I will try to play with the mds tunables and
> report back to your ASAP.
>
> So far I see that mds log contains a lot of errors of the following kind:
>
> 2016-10-02 11:58:03.002769 7f8372d54700  0 mds.0.cache.dir(100056ddecd)
> _fetched  badness: got (but i already had) [inode 10005729a77 [2,head]
> ~mds0/stray1/10005729a77 auth v67464942 s=196728 nl=0 n(v0 b196728 1=1+0)
> (iversion lock) 0x7f84acae82a0] mode 33204 mtime 2016-08-07 23:06:29.776298
>
> 2016-10-02 11:58:03.002789 7f8372d54700 -1 log_channel(cluster) log [ERR] :
> loaded dup inode 10005729a77 [2,head] v68621 at
> /users/mykola/mms/NCSHNO/final/120nm-uniform-h8200/j002654.out/m_xrange192-320_yrange192-320_016232.dump,
> but inode 10005729a77.head v67464942 already exists at
> ~mds0/stray1/10005729a77

This indicates the MDS metadata is corrupted. Did you do any unusual
operation on the cephfs? (e.g reset journal, create new fs using
existing metadata pool)

>
> Those folders within mds.0.cache.dir that got badness report a size of 16EB
> on the clients. rm on them fails with 'Directory not empty'.
>
> As for the "Client failing to respond to cache pressure", I have 2 kernel
> clients on 4.4.21, 1 on 4.7.5 and 16 fuse clients always running the most
> recent release version of ceph-fuse. The funny thing is that every single
> client misbehaves from time to time. I am aware of quite discussion about
> this issue on the ML, but cannot really follow how to debug it.
>
> Regards,
>
> -Mykola
>
> On 2 October 2016 at 22:27, John Spray <jsp...@redhat.com> wrote:
>>
>> On Sun, Oct 2, 2016 at 11:09 AM, Mykola Dvornik
>> <mykola.dvor...@gmail.com> wrote:
>> > After upgrading to 10.2.3 we frequently see messages like
>>
>> From which version did you upgrade?
>>
>> > 'rm: cannot remove '...': No space left on device
>> >
>> > The folders we are trying to delete contain approx. 50K files 193 KB
>> > each.
>>
>> My guess would be that you are hitting the new
>> mds_bal_fragment_size_max check.  This limits the number of entries
>> that the MDS will create in a single directory fragment, to avoid
>> overwhelming the OSD with oversized objects.  It is 100000 by default.
>> This limit also applies to "stray" directories where unlinked files
>> are put while they wait to be purged, so you could get into this state
>> while doing lots of deletions.  There are ten stray directories that
>> get a roughly even share of files, so if you have more than about one
>> million files waiting to be purged, you could see this condition.
>>
>> The "Client failing to respond to cache pressure" messages may play a
>> part here -- if you have misbehaving clients then they may cause the
>> MDS to delay purging stray files, leading to a backlog.  If your
>> clients are by any chance older kernel clients, you should upgrade
>> them.  You can also unmount/remount them to clear this state, although
>> it will reoccur until the clients are updated (or until the bug is
>> fixed, if you're running latest clients already).
>>
>> The high level counters for strays are part of the default output of
>> "ceph daemonperf mds.<id>" when run on the MDS server (the "stry" and
>> "purg" columns).  You can look at these to watch how fast the MDS is
>> clearing out strays.  If your backlog is just because it's not doing
>> it fast enough, then you can look at tuning mds_max_purge_files and
>> mds_max_purge_ops to adjust the throttles on purging.  Those settings
>> can be adjusted without restarting the MDS using the "injectargs"
>> command
>> (http://docs.ceph.com/docs/master/rados/operations/control/#mds-subsystem)
>>
>> Let us know how you get on.
>>
>> John
>>
>>
>> > The cluster state and storage available are both OK:
>> >
>> >     cluster 98d72518-6619-4b5c-b148-9a781ef13bcb
>> >      health HEALTH_WARN
>> >             mds0: Client XXX.XXX.XXX.XXX failing to respond to cache
>> > pressure
>> >             mds0: Client XXX.XXX.XXX.XXX failing to respond to cache
>> > pressure
>> >             mds0: Client XXX.XXX.XXX.XXX failing to respond to cache
>> > pressure
>> >             mds0: Client XXX.XXX.XXX.XXX failing to respond to cache
>> > pressure
>> >             mds0: Client XXX.XXX.XXX.XXX failing to respond to cache
>> > pressure
>> >      monmap e1: 1 mons at {000-s-ragnarok=XXX.XXX.XXX.XXX:6789/0}
>> >             election epoch 11, quorum 0 000-s-ragnarok
>> >       fsmap e62643: 1/1/1 up {0=000-s-ragnarok=up:active}
>> >      osdmap e20203: 16 osds: 16 up, 16 in
>> >             flags sortbitwise
>> >       pgmap v15284654: 1088 pgs, 2 pools, 11263 GB data, 40801 kobjects
>> >             23048 GB used, 6745 GB / 29793 GB avail
>> >                 1085 active+clean
>> >                    2 active+clean+scrubbing
>> >                    1 active+clean+scrubbing+deep
>> >
>> >
>> > Has anybody experienced this issue so far?
>> >
>> > Regards,
>> > --
>> >  Mykola
>> >
>> > _______________________________________________
>> > ceph-users mailing list
>> > ceph-users@lists.ceph.com
>> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>> >
>
>
>
>
> --
>  Mykola
>
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